Scouts, Guides, Youth Clubs or Schools, have your members ever tried rock climbing? Climbing works great as a bonding activity or as teambuilding not forgetting its a lot of fun too.
BMC Participation Statement
"The BMC recognises that climbing, hill walking and mountaineering are activities with a danger of personal injury or death. Participants in these activities should be aware of and accept these risks and be responsible for their own actions and involvement."